Giters

regclient / regclient

Docker and OCI Registry Client in Go and tooling using those libraries.

Geek Repo:Geek Repo

Github PK Tool:Github PK Tool

[Question] how to get all tags for a certain image version

tcurdt opened this issue · comments

commented

Question

I want to get a list of all tags for certain image.

This is what I tried:

regctl image inspect ghcr.io/tcurdt/foo:something
regctl tag ls ghcr.io/tcurdt/foo:something

And it seems like regctl tag ls ghcr.io/tcurdt/foo:something almost does what I want - except that it gives the same output as regctl tag ls ghcr.io/tcurdt/foo. So it's always ALL tags. Not for the specific image version.

Is this possible with the current version of regclient?
I haven't found it yet.

Context: I have foo:something also tagged as foo:build-1234 and would like to extract the build-1234 part.

Version

$ regctl version
VCSTag:     (devel)
VCSRef:     unknown
VCSCommit:  unknown
VCSState:   unknown
VCSDate:    unknown
Platform:   linux/arm64
GoVer:      go1.21.5
GoCompiler: gc

$ ls -la /nix/store/ | grep regctl
dr-xr-xr-x    3 root root       4096 Jan  1  1970 hq3dm22ks45g1sf2aplzma05h3c7cm4n-regclient-0.5.6-regctl

Environment

This is on nixOS on arm

Anything else

commented

The data for this doesn't come directly from any OCI APIs yet, so it would end up being a shell script to loop over every tag. This will be slow to poll the registry for each digest, so anything you can do to limit the possible tags to check the better.

$ digest="$(regctl image digest ghcr.io/regclient/regctl:latest)"

$ for tag in $(regctl tag ls ghcr.io/regclient/regctl --include 'v.*'); do
>   if [ "$digest" = "$(regctl image digest ghcr.io/regclient/regctl:${tag})" ]; then
>     echo "match $tag"
>   fi
> done

match v0
match v0.5
match v0.5.6
commented

That works - but OMG. I am curious what constraint has caused that API design of the OCI.

What I have done so far is to include the information also into the image meta data.
So it's just one call with regctl image inspect ghcr.io/foo/bar:latest and picking the info.

I am not sure which approach I prefer yet. Both feel ugly.

Thank you so much for you help.

commented

That works - but OMG. I am curious what constraint has caused that API design of the OCI.

The tag listing API only lists the tags, and not other metadata about those tags, like their digest:

https://github.com/opencontainers/distribution-spec/blob/v1.0.1/spec.md#content-discovery

There is a desire to make something that provides more data to the users, e.g. full descriptors rather than just the tag string. Some of that is seen in opencontainers/distribution-spec#222

I'm closing this for now since it's not a feature of regclient and won't be until changes happen upstream in OCI that would also need to be adopted by registries, but feel free to keep the conversation going here.